Three distinct areas of research are planned, which all deal with vitamin B12 transport and its relation to various diseases and abnormalities of such transport. The first study deals with the role of the pancreas in vitamin B12 transport, and involves the delineation of the nature and composition of normal and abnormal human pancreatic secretions in relation to vitamin B12. It is hoped thereby to clarify the role of the pancreas in vitamin B12 absorption and malabsorption. The second area of study involves the characterization of a macromolecular transcobalamin which is ubiquitous in human serum but about whose nature and function very little is known. The third area deals with an extensive analysis of clinical, laboratory and epidemiological data compiled on the large, heterogenous patient population with pernicious anemia at LAC-USC Medical Center. Particular attention will be paid to potential subgroups within this disease entity. In addition it is planned to analyze gastric juice from such patients with an intrinsic factor radioimmunoassay to be developed to better define the nature of the defect in various types of pernicious anemia and gastritis. Methodology to be used in all the above studies includes use of electrophoretic, chromatographic, and immunologic techniques, and cell uptake studies using various in vitro cell systems.